Name: wheatstone bridge output for strain gauge design
Uploaded: 2024-04-11T12:48:31.000Z
Duration: 1 min 15 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Biology

BIO.2

BIO.2.D

design-example-strain-gauge-bridge-or-wheatstone-bridge

Design Example: Strain Gauge Bridge or Wheatstone Bridge

מד מאמץ, מתמר הממיר מאמץ מכני לאותות חשמליים, משמש לעתים קרובות למדידת כוח.
תפקיד המהנדס כולל תכנון מעגל גשר ויטסטון, בעל מדי מאמץ בכל זרוע, וזיהוי ההגברה הנדרשת למתח היציאה. כאן, ההנחה היא כי הכוח המופעל מגביר את ההתנגדות של שני מדי מאמץ בעוד ההתנגדות פוחתת בשני האחרים. כמו כן, הקשר בין מתח היציאה של הגשר לבין השינוי בהתנגדות ידוע.
ניתן להשיג זאת באמצעות משפט תבנין.
לדעת את מתח הכניסה, הזרמים בענפים העליונים והתחתונים נקבעים לראשונה. ערכים אלה מוחלפים לאחר מכן בחוק אוהם כדי לחשב את מתח תבנין.
המקור מוסר כדי לחשב את התנגדות תבנין, וההתנגדות המקבילה נקבעת בצורה פשוטה.
מהמעגל המקביל של תבנין, מתח היציאה של הגשר מחושב באמצעות כלל חלוקת המתח.
השוואת הקשר המתקבל עם היחס הידוע מאפשרת לקבוע את רווח המגבר הדרוש לתכנון המעגל כך שיעבוד בטווח הרצוי.

דוגמה לעיצוב: גשר מד מתח

<div style="direction:rtl">השימוש במדדי מתח כמתמרים להמרת מתח מכני לאותות חשמליים הוא נוהג נפוץ ביישומים הנדסיים שונים. מדי מתח אלה משולבים לעתים קרובות במעגלי גשר ויסטון כדי למדוד במדויק פרמטרים כגון כוח או לחץ. בהקשר זה, כל אלמנט בתוך המעגל מפגין התנגדות שעוברת שינויים עדינים כאשר הוא נתון למאמץ מכני. המטרה העיקרית היא להמיר שינויים זעירים בפלט מתח קטן לפלט מתח מובחן יותר, אותו ניתן לקרוא בנוחות באמצעות מד מתח. בתפקידו של המהנדס, האחריות כוללת יצירת תכנון מד מתח וקביעת ההגברה הדרושה לשקף שינויים בהתנגדות בצורה מדויקת. זה מסתמך על יישום המשפט של תבנין, הקובע את הקשר בין מתח המוצא של מעגל הגשר לבין שינויים בהתנגדות. ההליך מתחיל בחישוב מתח תבנין, הדורש קביעה ראשונית של זרמים בתוך הענפים העליונים והתחתונים של המעגל כאחד. כתוצאה מכך, ערכי הזרם המחושבים הללו מוחלפים בחוק אוהם כדי לגזור את מתח התבנין. במקביל, התנגדות תבנין נקבעת על ידי הסרת מקור המתח בתצורה פשוטה. המעגל המקביל של תבנין מוצא את מתח המוצא של הגשר באמצעות כלל חלוקת המתח. התוצאה הקריטית של ניתוח זה מאפשרת קביעה מדויקת של רווח המגבר הנדרש לתכנון המעגל לפעול ביעילות בטווח הפעולה שצוין.</div>

מד מאמץ, מתמר הממיר מאמץ מכני לאותות חשמליים, משמש לעתים קרובות למדידת כוח.
תפקידו של המהנדס כרוך ...

Education

JoVE Core

Electrical Engineering

הנדסה חשמלית

Unit 1

יחידה 1

DC Circuit Analysis

ניתוח מעגלי DC

KEY TERMS AND CONCEPTS

מונחי מפתח ומושגים

wheatstone bridge output for strain gauge design

A strain gauge and Wheatstone bridge work together to turn mechanical strain into an electrical signal. In engineering, this setup is often used to measure force or pressure. Each part of the bridge has a resistance that changes slightly when strain is applied.

The main goal is to turn a very small voltage output into a larger, easier-to-read signal. A voltmeter can then measure that output more clearly. To do this, an engineer designs the strain gauge circuit and figures out how much amplification is needed so the resistance change is shown accurately.

The analysis uses Thevenin's theorem, which links the bridge output voltage to changes in resistance. First, the Thevenin voltage is found by calculating the currents in the upper and lower branches of the circuit. Those currents are then used with Ohm's law to determine the voltage.

Next, the Thevenin resistance is found by removing the voltage source and simplifying the circuit. The Thevenin equivalent circuit is then used with the voltage division rule to find the bridge output voltage. This result helps determine the amplifier gain needed for the circuit to work in the correct operating range.

Wheatstone Bridge Output for Strain Gauge Design

wheatstone-bridge-output-for-strain-gauge-design

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thevinin's theorem

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design example: strain gauge bridge or wheatstone bridge

A strain gauge and Wheatstone bridge work together to turn mechanical strain into an electrical signal. In engineering, this setup is often used to measure force or pressure. Each part of the bridge has a resistance that changes slightly when strain is applied. The main goal is to turn a very small voltage output into a larger, easier-to-read signal. A voltmeter can then measure that output more clearly. To do this, an engineer designs the strain gauge circuit and figures out how much...

key terms and concepts

Learn how a strain gauge and Wheatstone bridge convert strain into voltage, and how Thevenin's theorem helps find the amplifier gain needed.

Wheatstone Bridge Output for Strain Gauge Design | JoVE K12

JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

electrical engineering

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Wheatstone Bridge Output for Strain Gauge Design

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